Primary Stability of Dental Implants in Human Jawbones: Experiments & FE Analyses

Area of Science:

• Biomaterials Science
• Mechanical Engineering
• Dental Implantology

Background:

• Primary stability (PS) is crucial for osseointegration and long-term success of dental implants, especially with immediate loading protocols.
• Accurate pre-operative evaluation of PS can enhance surgical planning and treatment outcomes.
• Current PS assessment methods have limitations in precision and objectivity.

Purpose of the Study:

• To objectively measure PS using biomechanical testing and homogenized finite element (hFE) analysis.
• To digitally estimate PS from micro-computed tomography (μCT) reconstructions.
• To compare the accuracy of hFE analysis with conventional PS assessment techniques.

Main Methods:

• Bone samples from human donors were analyzed using μCT.
• Dental implants were inserted, and metrics including bone volume fraction (BV/TV), insertion torque (IT), and resonance frequency analysis (RFA) were measured.
• Mechanical testing determined experimental ultimate force (UFexp), while hFE simulations estimated ultimate force (UFsim).

Main Results:

• hFE analysis (UFsim) showed a higher correlation with experimental ultimate force (UFexp) (R² = 0.85) compared to BV/TV (R² = 0.61), IT (R² = 0.50), and RFA (R² = 0.38).
• All assessed variables demonstrated a statistically significant linear correlation with UFexp (p < 0.01).
• UFsim proved to be a more reliable and objective indicator of PS than IT and RFA.

Conclusions:

• Pre-operative hFE analysis, despite requiring μCT data and facing numerical convergence challenges, is a promising tool for estimating PS.
• hFE analysis offers higher accuracy for PS estimation compared to current clinical techniques.
• This digital approach has the potential to significantly improve dental implant surgical planning and patient outcomes.